There is also the important point that stage mics are designed to take the rough and tumble of work on the road and being left overnight in a freezing truck.  This kind of treatment will shorten the life of a studoio mic.

Lay out the microphones on stage to correspond with the mixer fader layout, i.e. left to right on stage and the mixer. This is especially important on vocal microphones to avoid confusion. Label the mics and mark that mic on the mixing desk.

It is a good idea to either colour code or number your mics and use that code throughout, including the leads.  In other words, input one goes to lead one and is attached to mic one.  If every XLR and mic is numbered in this way, you will avaiod confusion.

Instrument amplification, electric pianos, synths, etc., may be miked but it is preferable to directly inject them into the mixer via a D.I. box or straight from the pre-amplifier output which may be fitted to some amplifiers. Direct injected signals are always much cleaner because they avoid any distortion that may be introduced by using a microphone. Most guitar amps today have D.I. jacks on the back, though they are labelled 'speaker simulation.'

(Never under any circumstances connect an amplifiers loudspeaker output to the mixers input. The output voltage is high enough to destroy the preamp in most desks!)

Microphone Positioning

Leads should be well clamped to the mic body as they are constantly wrenched. Nine times out of ten, the Shure SM 58 is used for vocals. It is crisp, clear, cheap and reliable.

Miking up a drum kit is regarded in the rock scene as the highest of the audio high arts, but in reality, it is fairly simple. The clue is to have a really great sounding drum kit. (Or as you will often hear, 'You can't polish a turd!')

Snare drum microphones should be placed above the top skin near the edge. You may need to place a second mic on the underside to pick up the snare 'rattle' in bigger gigs where every part of the drums has to be close miked.

There are two alternatives to conventional miking up for drums. Firstly, you can place contact mics directly onto the skins or on the inside of the drum's body.  The other alternative is to place triggers onto the skins and run them to a digital drum controller such as the dDrum. The advantage is that one can change sounds at the touch of a button and there is no need for any further dynamic processing.

Amplification

In the good-old bad-old days, we always were told that the speakers had to have double the power handling of the amps. The result was the amps went into distortion and the peaks that came off the distortion blew the horns.

Today we have sophisticated protection circuits and better horn construction and cooling, so amps and speakers should be about as powerful as one another.

There was a time when we all practised the dark art of DIY speaker manufacture. Speaker cabinets were expensive and often loaded with cheaper speakers. This was largely because transport costs were high and retail outlets wanted 60% to 100% mark-up. Today, companies like JBL, RCF and EV sell full range systems for as little as 300 Pounds for a 450 Watt full range speaker with horn and two 15" bass drivers. That is less than the cost of building it yourself!

If you are playing a large hall or an open air venue, you should take a close look at line array systems. The speakers are hung in a long curve from the top of the stage and create a powerful pressure wave across the audience that does not suffer from the ill-effects of temperature inversion.  This means that the power is used to provide lots of sound for the audience and not to annoy people living five miles away.

Testing

After you have connected the components of the system, but before it is turned on, check the wiring thoroughly. This is particularly important if you are using an electronic crossover unit, as it is possible to accidentally connect the bass section to the horn drivers, which could result in permanent damage.  (Again, if you lable your cables, this should not happen!)  Switch the amps on last when you power up and first when you power down.  Always use the switches on the amplifiers themselves as these should have a protective circuit that prevents massive clicks damaging the speakers.

NEVER THROW ONE MASTER SWITCH FOR THE WHOLE SYSTEM.

When the equipment is on, check that all amplifiers are functioning and check the loudspeakers and horns individually. If there is a fault, the chances are that it is a cable, so always carry lots of spare cables. If this is not the case, you must isolate the fault. For instance, try connecting the speaker, which is not working to a different amplifier. If it works you should check the original amplifier with a loudspeaker and cable which you know to be working. The separate pieces of equipment can be eliminated in this way until you are left with one faulty item.

Whilst it is not always possible to carry spares of everything, it is a good idea to carry a tool kit containing a mains test screwdriver, wire cutters, strippers, soldering iron and solder, pliers, spare plugs and connectors and spare fuses. You may not be able to repair every possible fault but armed with the above you can remedy the minor ones (which most faults are), on the spot. Remember, never leave home without spare cables.

Sound

Getting a good sound is very much a question of experience. It is also very true that a poor band or musician will still sound poor when amplified. There is nothing you can do to make a bum note sound right and there is no way to keep a sloppy drummer on the beat. However, even when it is the band's fault, you as sound technician will probably get the blame!

Also remember that the hall or venue is the most important part of your sound system. It is very difficult to get a poor sound in a Roman Arena. It is close to impossible to get a good sound in a square room with a tin roof (without hanging lots of heavy drapes on the ceiling and on some of the walls).

An old, but very effective trick when dealing with a difficult hall, is to use a spectrum analyser that works in real time (i.e. the LEDs or the curve falls instantly) to see where the problem frequencies are. This is done by putting pink noise (random noise of equal energy at all frequencies) through the speakers and setting up the graphic equalizers until the analyser shows all frequencies to be more or less level. Cut the pink noise and see which frequencies take the longest to die down. These are going to be where you will have the most problems. Bring them down on the equalizer.

Large systems use a stereo electronic crossover on the mixer outputs to split the sound into two or more sections (i.e. bass, middle, treble) Each individual sound is sent to an amplifier and loudspeaker cabinet which is specially designed to handle these particular frequencies. The crossover has a separate gain control on each section.

Once you are satisfied that everything is as it should be, you can begin to position the channels in the stereo spectrum by means of the pan controls. One feature, which is standard on most larger mixers and is a great aid to live mixing, is the ability to route the input channels to subgroups. If seven microphones are placed around a drum kit and fed to seven mixer channels, if it became apparent during the show that the kit was not loud enough it can be brought up on the subgroup faders rather than the engineer trying to raise seven channel faders simultaneously. It also means that the entire group can be fed via an auxiliary send to an effect such as a compressor.

You can also use the subgroups as an easy way to feed the monitor (or foldback) mix. Just take a direct out from each group mix and feed it into one of your monitor amps. On larger systems a whole separate monitor mixing system is used using specialized mixers that can give every musician a different mix.

A cheap trick to getting a good sound with a band is to give each instrument and voice a different part of the frequency spectrum as far as possible. Try giving the upper highs and lower bass to just bass and drums. Cut the highs on backing vocals and boost the upper mids to lead vocals. Try keeping keyboards in the back and don't give lead guitars too much bass, if any. Keep effects down to a minimum and after years of practice, you too can become an audio engineer!